Re: [PATCH] loop: add some basic read-only sysfs attributes

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Jul 29, 2010 at 04:22:50PM +0200, Kay Sievers wrote:
> On Thu, Jul 29, 2010 at 16:06, Milan Broz <mbroz@xxxxxxxxxx> wrote:
> > On 07/29/2010 03:47 PM, Kay Sievers wrote:
> >> On Thu, Jul 29, 2010 at 15:33, Milan Broz <mbroz@xxxxxxxxxx> wrote:
> >>> Create /sys/block/loopX/loop directory and provide these attributes:
> >>>  - backing_file
> >>>  - autoclear
> >>>  - offset
> >>>  - sizelimit
> >>>
> >>> To be used in util-linux-ng (and possibly elsewhere like udev rules)
> >>> where code need to get loop attributes from kernel (and not store
> >>> duplicate info in userspace).
> >>
> >> Isn't it that the loop attributes are created _after_ the loopdev is
> >> registered? That would make it hard to use these attributes from udev,
> >> as the event is already running while they are created.
> >
> > First 8 loop devices are registered always (without backing file),
> > so you have wait for change event initiated from fd set ioctl anyway...
> > (backing file attribute is empty in that case)
> 
> Ah, so we are sure, we always get a 'change' event, and before that,
> none of these values are ever useful to read? I mean, there will not
> be attributes that are interesting during an 'add' event?

I think the patch does not change the current behavior. It exports
details about loopdevs to userspace by /sys. This is the primary goal
of the patch.

    Karel

-- 
 Karel Zak  <kzak@xxxxxxxxxx>
 http://karelzak.blogspot.com
--
To unsubscribe from this list: send the line "unsubscribe util-linux-ng" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux